P1

function X = P1(N)
    RuleForF = 'F-b+FF-F-FF-Fb-FF+b-FF+F+FF+Fb+FFF';
    X = 'F-F-F-F';
    teta = pi/2;
    alfa = 0;
    m=1;  
    n=1; 
    i=1; 
    j=1;   
    while i<N+1
        len_X = length(X);
        while j<len_X+1
            if X(j) == 'F'
                while m<length(RuleForF)+1
                    H(n) = RuleForF(m);
                    m=m+1;
                    n=n+1;
                end
            elseif X(j)=='-'
                H(n) = '-';
                n=n+1;
            elseif X(j) =='+'
                H(n) = '+';
                n=n+1;
            end 
            m=1;
            j=j+1;
        end
        i=i+1;
        X=H;
        j=1;
        n=1;
    end
    line = animatedline; i=2;j=1;
    x(1)=0;
    y(1)=0;
    addpoints(line,x(1),y(1));
    drawnow
    while j<length(X)+1
        if X(j) == 'F'
                x(i) = x(i-1)+cos(alfa);
                y(i) = y(i-1)+sin(alfa);
                addpoints(line,x(i),y(i));
                i=i+1;
                drawnow
        elseif X(j)=='-'
                alfa = alfa-teta;
        elseif X(j) =='+'
                alfa = alfa+teta;
        end 
        j=j+1;
    end
end